1. Field of the Disclosure
This disclosure relates generally to wireless electromagnetic telemetry for use in wellbore operations.
2. Background of the Art
Wellbores are drilled in subsurface formations for the production of hydrocarbons (oil and gas). Modem wells can extend to great depths, often more than 1500 meters (or 15,000 ft.). Various methods have been used for communicating information from the surface to devices in the wellbore, both for production wells and during drilling of wells. In production wells, hard wired, acoustic and electromagnetic telemetry methods have been proposed. During drilling, the predominant telemetry method is mud pulse telemetry wherein information from the surface and/or downhole is transmitted through via mud pulses created in the mud flowing mud through drill string. The mud pulse telemetry is extremely slow, such as a few bits per minute. The acoustic and electromagnetic telemetry systems have not been very reliable and successful. Hard wiring can be problematic due to the harsh down-hole environment and is also very expensive. There is a need for a more reliable telemetry system for use in well operations.
The present disclosure provides an electromagnetic telemetry system and methods that addresses some of the above-noted issues.